A vacuum pump may comprise a vacuum pumping mechanism comprising a rotor supported for rotation by a drive shaft, a first bearing assembly for controlling movement of the rotor away from its normal position during rotation of the drive shaft and a back-up bearing assembly for limiting said movement. Periodically, the vacuum pump requires maintenance and servicing to avoid low performance or failure.
The discussion above is merely provided for general background information and is not intended to be used as an aid in determining the scope of the claimed subject matter. The claimed subject matter is not limited to implementations that solve any or all disadvantages noted in the background.